Unified firewall and port forward ruleset for multi-WAN setup

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I use a dual-WAN setup where I have a main cable broadband interface that's backed up by a failover mobile broadband interface and I use default gateway switching for the failover/switch-back. I use several port forward and firewall rules for incoming traffic that are currently assigned to the main WAN interface only. Is there any elegant way of making them apply to both primary and the secondary WAN that is short of manually duplicating them? Would the use of floating firewall rules and assigning port forwards to both WAN networks do the trick?